I'd suggest you call around to any stores in your area that make custom signs and ask if they do vinyl graphics. If they say yes, then tell them what you'd like to do. Some will say OK, but others won't be able to handle it on account of the small size. Some will even allow you to create custom picture cubes, but apparently the best results are made with something called a "Gerber" system (as in the baby food), which is very rare in sign shops, and thus very expensive. If you're just looking for plain vanilla monocoloured stickers, then pretty much any place should do just fine, bringing the price down dramatically (eg. about $15 Canadian/cube vs. about $200, before the eonomies of scale kick in). Good luck with your project.